1. Technical Field
The present invention relates to a resonator, an oscillator, an electronic apparatus, a physical quantity sensor, and a mobile object.
2. Related Art
In the related art, a resonator device using quartz crystal has been known. Such a resonator device has an excellent frequency temperature behavior, and thus, it is broadly used as a reference frequency source or a transmission source of various electronic apparatuses.
A tuning fork type resonator device disclosed in JP-A-2009-130456 includes a resonator element including a base portion, a pair of vibrating arms which extend from one end side of the base portion, a connection portion which is positioned at the other end side of the base portion, and a linkage portion (constricted portion interposed between cut-outs) which is positioned between the base portion and the connection portion and links those, and can decrease vibration leakage by forming the linkage portion. JP-A-2009-130456 discloses that a width W2 of the linkage portion may be equal to or less than 50% of a width W1 of the base portion.
However, in the resonator device disclosed in JP-A-2009-130456, a weight portion (hammer head) is not provided on a distal end portion of each vibrating arm. When the weight portion is provided in the vibrating arm, distortion easily occurs in the vibrating arm at the time of the excitation, and the vibration leakage tends to increase to that extent. When the weight portions are formed in the vibrating arms having the same length, in order to realize high performance of the resonator device, an effect of the vibration on the base portion due to flexural vibration necessarily increases, and the vibration leakage also tends to increase. Accordingly, when the weight portion is provided in the vibrating arm, it is not clear that the vibration leakage can be sufficiently decreased by only setting the width W2 to be equal to or less than 50% of the width W1.
The vibration leakage of the resonator device greatly depends on a hardness of a fixing member (generally, a metal bump or a conductive adhesive) which fixes the resonator device to a package. That is, even when the width W2 is set to be equal to or less than 50% of the width W1, the vibration leakage hardly sufficiently decreases depending on the hardness of the fixing member. In JP-A-2009-130456, the description of the hardness of the fixing member is not disclosed, and therefore, a relationship between the hardness of the fixing member and the width W2 (W2/W1) is not clear.